Like anyone, they think their side is the right one and so want a good outcome for them. As such, they are biased in their thinking about others from their side, and many are not above exerting undue influence or acting in a consciously dishonest way.

Especially if there's a cosy relationship between the police and the IPCC and a personal familiarity, it is very easy to ask what's happening and express an opinion in a way that prejudices a case.

Police lie and go against their sworn duty all the time. I have been involved in several dozen court cases and around many more, well into three figures. In the majority of cases police have exaggerated and misled with their evidence, and on numerous occasions given false testimony.

The police response to the cases we all know about such as Ian Tomlinson and Jean Charles de Menezes should be enough to show anyone what happens when they've done something wrong.

In what way is that misleading? I've made clear, that's the oes that are independently investigated.

Doesn't that bother you? Thousands of complainants appeal against local police investigation of themselves, but over 80% of the appeals fail and even though the complainant believes the police are not fit to investigate themselves, they almost always get to do it anyway. With predicatable results.

Knowledge of policing and what the police are supposed to do and what they're not allowed to do should be a prerequisite, absolutely. That doesn't mean someone who has actually done the job.

[/quote]And whilst I understand why you say "the only background that should exclude an independent investigator is one in the police" sometimes it takes a poacher to catch a poacher.[/quote]

That's just nonsense in this context. The fact that the police exonerate themselves several times more often than when they're independently investigated points towards that. Should people only be magistrates if they've got criminal convictions?

This is a matter of justice, and for justice to work it has to be clearly fairly administered. This system clearly does not do that. The police investigating themselves is like MPs deciding their own pay rises and sorting out their own expenses.